• KSBB Journal
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• 제24권1호
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• pp.70-74
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• 2009

본 연구에서는 음식물쓰레기를 당화시키기 위해 섬유소분해효소를 효율적으로 배양하고자 먼저 refill하는 멘델배지의 농도를 0.5%로, 새로운 배지의 주입시간을 12시간으로 결정하였다. Flask 레벨에서는 fill-and-draw 방법으로 12시간 단위로 연속배양한 결과, amylase 활성은 300시간까지 1.0 U/mL 내외로 유지되었으며, FPase 활성은 156시간까지 0.40 U/mL 이상으로 유지되었다. 이때의 효소생산성은 amylase 3.49 U/L. hr, FPase 1.02 U/L. hr 이었다. 10 L에서는 batch, fed-batch, fill-and-draw 방법으로 효소를 생산한 결과 batch에서 가장 높은 효소생산성을 나타내었으며, 그다음은 fed-batch 이었다. Batch에서의 효소생산성은 amylase 42.30 U/L. hr, FPase 5.60 U/L. hr, fed-batch에서는 각각 23.03, 2.76 U/L. hr 이었다. 그리하여 T. inhamatum KSJ1을 이용한 섬유소분해효소의 연속배앙에서 10 L 생물반응기에서 fed-batch 빙법이 가장 효율적이었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권5호
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• pp.340-344
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• 2000

Microbial oxidation of D-sorbitol to L-sorbose by Acetobacter suboxydans is of commercial importance since it is the only biochemical process in vitamin C synthesis. The main bottleneck in the batch oxidation of sorbitol to sorbose is that the process is severely inhibited by sorbitol. Suitable fed-batch fermentation designs can eliminate the inherent substrate inhibition and improve sorbose productivity. Fed-batch sorbose fermentations were conducted by using two nutrient feeding strategies. For fed-batch fermentation with pulse feeding, highly concentrated sorbitor (600g/L) along with other nutrients were fed intermittently in four pulses of 0.5 liter in response to the increased DO signal. The fed-batch fermentation was over in 24h with a sorbose productivity of 13.40g/L/h and a final sorbose concentration of 320.48g/L. On the other hand, in fed-batch fermentation with multiple feeds, two pulse feeds of 0.5 liter nutrient medium containing 600g/L sorbitol was followed by the addition of 1.5 liter nutrient medium containing 600g/L sorbitol at a constant feed rate of 0.36L/h till the full working capacity of the reactor. The fermentation was completed in 24h with an enhanced sorbose productivity of 15.09g/L/h and a sorbose concentration of 332.60g/L. The sorbose concentration and productivity obtained by multiple feeding of nutrients was found to be higher than that obtained by pulse feeding and was therefore a better strategy for fed-batch sorbose fermentation.

• Fisheries and Aquatic Sciences
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• 제21권10호
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• pp.33.1-33.11
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• 2018

As a process for commercial application, production of reducing sugar, antioxidant, and DNA protective compounds from shrimp-shell powder was investigated in a fed-batch biodegradation using Bacillus cereus EW5. The fed-batch biodegradation was operated in a 5-L bioreactor for 96 h according to three times pulse-feeding strategy. On the basis of the equal working volume (3 L), the fed-batch biodegradation showed a better production of the target compounds than the batch biodegradation, with higher cell density and shortened biodegradation period. The maximum values of the target compounds were 0.297 mg/mL of reducing sugar, 92.35% DPPH radical scavenging activity, 98.16% ABTS radical scavenging activity, and 1.55 reducing power at $A_{700}$, which were approximately 12.1, 3.4, 5.2, and 8.4% enhanced, respectively, compared with those obtained from the batch biodegradation. The fed-batch culture supernatant also showed the enhanced DNA damage inhibition activity than the batch culture supernatant. As a result, the fed-batch biodegradation accompanied by high cell density could produce more useful compounds, enabling an increase in the reutilization value of shrimp-shell waste.

• KSBB Journal
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• 제14권3호
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• pp.284-290
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• 1999

우수한 셀룰로오스 생산 균주인 Acetobacter xylinum BRC5의 교반배양에 의한 셀룰로오스 생산성을 향상시키기 위하여 fed-batch 배양을 하였으며, 기질공급속도, 기질 공급량 및 용존 산소의 영향을 검토하였다. 초기 glucose 양을 변화시켜 회분배양하였을 때 glucose 농도가 10 및 20 g/L인 경우 셀룰로오스 생산량은 각각 2.05와 4.10 g/L이였으며 glucose에 대한 셀룰로오스 수율 (Yp/s)은 0.21이었다. 초기 glucose 농도 40g/L일 때 셀룰로오스 수율을 향상시키기 위해서 초기 glucose 농도 20 g/L에서 회분배양을 시작하여 glucose가 gluconic acid로 완전히 전환된 시점부터 추가적으로 glucose를 공급하여 fed-batch 배양기간에 glucose 공급속도는 셀룰로오스 생산성에 큰 영향을 미쳐 20g/L의 glucose를 2.22 g/L.h의 속도로 9시간 첨가하여 fed-batch 배양한 결과 셀룰로오스 생성량이 10 g/L로 가장 우수하여 초기 glucose 농도 20 g/L로 회분배양하였을 때 비하여 약 2배 증가하였으며, $Y_{P/S}$도 0.26으로 현저히 향상되었다. 또한 동일조건으로 fed-batch 배양하면서 glucose 공급량을 증가시켜 40g/L의 glucose를 추가적으로 첨가한 경우 셀룰로오스 생산량은 10.7g/L는 거의 증가되지 않았으며, $Y_{P/S}$가 0.18로 감소하였다. 이는 셀룰로오스 농도가 증가함에 따라 산소 공급이 부족하기 때문이므로 용존산소(DOT)를 2~15% 포화범위에서 조절하여 fed-batch 배양했을 때 DOT를 10% 수준으로 유지하면서 fed-batch 배양기간에 40g/L의 glucose를 추가공급 했을 때 셀룰로오스 생성량은 15.3 g/L로 증가되었고 이때 $Y_{P/S}$는 0.26로 향상되었다. 이는 DO를 제어하지 않는 경우에 비하여 셀룰로오스 생성량이 1.5배 증가한 결과이다.

• KSBB Journal
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• 제13권4호
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• pp.411-417
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• 1998

The possibility of application of membrane type immobilized adsorbent to the fed-batch or perfusion culture system with anchorage-independent cells as well as batch system was investigated. The improvement in cell density and cell viability due to the combination of immobilized adsorbent with each culture system was evaluated for the investigation, and the optimum culture system employing immobilized adsorbent system was suggested based on the results. It was observed that the system with immobilized adsorbent showed better cell growth and cell viability than that without immobilized adsorbent in every operation system of batch, fed-batch, and perfusion. In case of batch system, 200% improvement of maximum cell density was observed in the system where ammonium chloride was added on purpose. And 50% improvement of maximum cell density was observed in the fed-batch system where ammonium ion accumulates significantly, while small increase in maximum cell density was observed in the perfusion system where dilution of waste byproducts exists. Especially, the fed-batch system showed the most significant improvement on cell growth because both compensation of nutrient and removal of ammonium ion occurred simultaneously in the system. Therefore a combined system of immobilized adsorbent and fed-batch operation could be suggested as an optimum system with in situ removal of ammonium ion.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.11-17
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• 2001

To enhance the productivity and activity of nitrile hydratase in Rhodococcus rhodochrous M33, a glucose-limited fed-batch culture was performed. In a fed-batch culture where the glucose was controlled at a limited level and cobalt was supplemented during the fermentation period, the cell mass and total activity of nitrile hydratase both increased 3.3-fold compared to that in the batch fermentation. The productivity of nitrile hydratase also increased 1.9-fold compared to that in the batch fermentation. The specific activity of nitrile hydratase in the whole cell preparation when using a fed-batch culture was 120 units/mg-DCW, which was similar to that in the batch culture.

• 한국미생물·생명공학회지
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• 제29권4호
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• pp.234-239
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• 2001

천연풍미소재로 정미성 nucleotide 함량이 높은 효모추출물을 만들기 위해서 세포내 RNA 함량이 높은 효모균주 S , cerevisat MTY 62를 선별하여TRh, 당밀과 CSL배지로 발효조 회분배양과 유가배양을 수행하였다. 여러가지 단양한 간헐적 유가배양 중에서 40% 당밀과 20% CSL의농축기질액을 50ml 다섯번 공급하는 간헐적 유가배양 (IFB-IV) 에서 최대 세포농도는 33.8g-DCW/1 RNA 농도는 5221 mg/l RNA 함량은 153 mg-RNA/g DCW 값을 나타내었다. 일정속도의 유가배양에서는 기질 요액(40% molasses, 20% CSL)을 배양 9~13시간에서는 49 ml/h 13~21 이시간에서는 24 ml/h 그 이후로는 18 ml/h 로 기질공급속도를 단계적으로 감소시키는 유가배양 (CFB-III) 에서 42.7g-DCW-1 최대 세포농도를 5545 mg RNA/1의 RNA농도를 보여, 간헐적 및 일정 속도 유가배양 중에서 가장 높은 세포농도와 RNA 농도 값을 나타내었다. 그러나 RNA 함량 면에서는 가장 낮은 130 mg-RNA/g-DCW 값을 보여다. 즉 세포농도가 높을수록 RNA 함량은 감소하는 경향을 나타내었다. 이 상의 두 가지 유가배양에 대해 비증식속도 ($\mu$)에 따른 RNA 함량을 조사한 결과, $\mu$값이 증가할수록 RNA 함량도 증가하였다. 그러나 일정한 $\mu$에서는 일정속도의 기질공급 방식보다 간헐적 기질공급 방식이 더 높은 RNA 함량을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.203-207
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• 1998

Fed-batch fermentations with different feeding media were carried out in order to increase the productivity of invertase expression using a recombinant Saccharomyces cerevisiae containing plasmid pRB58. Two batch cultures showed the expression of the SUC2 gene at a low concentration of glucose, suggesting that glucose concentration could be used as a control variable in a fed-batch operation mode. In the fed-batch culture by feeding the basal medium, cell mass and specific invertase activity did not increase much as compared with the simple batch culture. A series of fed-batch cultures revealed that the sucrose-supplemented medium increased cell mass whereas the enriched medium did specific invertase activity. To capitalize on the synergism of the sucrose-supplemented medium and the enriched medium, the sucrose-supplemented enriched medium was used as a feeding medium. The fed-batch culture using this medium resulted in a 2.4-fold increase in cell mass and a 1.9-fold enhancement in specific invertase activity compared with those of the batch culture. The increase in cell mass and specific invertase activity led to a marked increase in total invertase activity, 250U/ml, which was 6.3 times higher than that of the batch culture.

• 한국식품영양학회지
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• 제11권6호
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• pp.617-621
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• 1998

The production of red pigment from glucose by fed-batch culture of Monascus anka was investigated. In batch culture using fermentor, 200 rpm of agitation speed, 1vvm of aeration volume, and 10% (v/v) of inoculum size were optimal, respectively. The red pigment production was increased by removal of wall-attached mycelium. In an intermittent feeding fed-batch culture, dry cell weight increased to 30 g/l, adn the red pigment content reached 350 of absorbance at 495nm. In a continuous feeding fed-batch culture, dry cell weight increased to 22g/l, and the red pigment content reached 190 of absorbance at 495nm.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.356-359
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• 2000

Xylitol의 생산성을 높이기 위해 two-stage fed-batch를 수행하였다. Glucose가 고갈되어 pH가 5.7에서 올라가면 glucose를 공급하는 방법에서 최종세포의 OD 185.0과 최종 ethanol 농도 1.0 g/L를 얻었다. 산소전달에 대한 xylitol의 생성 영향에서는 통기량 1 vvm에서 500 rpm의 교반속도일 때 xylitol 수율 55.2%와 생산성 $2.19\;g-xylitol/L\;{\cdot}\;h$를 얻었다.